This invention relates to dishwashers and, in particular, to the design of the chassis of such a machine.
Dishwashers are usually manufactured by mounting a tub, comprising a bottom, three walls, and a roof formed of sheet metal, on a base which is manufactured by joining several beams and/or metal plates by bending, welding, or screwing operations to form a support on which an outer shell, if any, and related components are fastened. The method is troublesome and time-consuming, and has the draw-back that it is very difficult to achieve a construction which has sufficient stiffness because of the cumulative mechanical play provided by the large number of joints connecting the different parts. Thus, handling during transportation between manufacturer and customer often causes distortion and misalignment between the parts of the machine.
It is also previously known from DE 2,420,302 to design the dishwasher so that the upper part of the tub, which is produced from sheet metal, is placed on a foamed plastic base, with a labyrinth seal placed between the parts. According to this arrangement, the pumps and other components are installed on the base, thus providing for easy assembly. The patent publication, however, does not describe a method for increasing the rigidity of the dishwasher.
In order to facilitate dishwasher assembly, it is also known to produce an upwardly open base box made of plastic and having means integrated within the box for mounting the dishwasher components into the box. The tub is placed above the box and is pivotally supported on a shaft. This design, however, still does not solve the lack of stiffness problem mentioned above.